1. Field of the Invention
This invention pertains to liquid chemical containers and, more particularly, to a closed system for emptying from such containers harmful chemicals such as acids, carcinogens and pesticides.
2. Background Information
A significant need has developed to provide means to empty liquid chemical containers so that the risk of human contact is absolutely minimal. This is particularly important in the case of harmful chemicals such as those just noted. The State of California has restricted the open pouring of pesticides for the last four years. That state's legislation and subsequent regulations only control open pouring, and do not address themselves to the possibilities of subsequent contamination through human contact with uncleansed containers or extracting devices. In addition, the Federal EPA is currently in the process of examining the need for restricting open pouring.
In order to provide background for a complete understanding of the present invention, and in order that one may appreciate the precise context of the present invention, reference may be made to the following publication:
"AGRI-CHEMICAL AGE" for September-October 1978, page 19.
That publication describes a "product of the month", which is a closed pesticide transfer system comprising an inexpensive built-in probe, normally installed in the drum by chemical formulators, and a standardized quick coupler. However, in the described system, hand pouring or open pouring from the container is still possible through a two-inch opening for customers not equipped with the complete closed system. In other words, the user has the option of using a special, mating extraction device, or not using it.
Further background material may be obtained from the following U.S. Pat. Nos.: 4,108,336, 4,150,771, and 4,245,760. The first and third of this group of patents relate to chemical container arrangements that may be adapted for use in a closed system. However, the container arrangements in these patents do not completely inhibit open pouring or exposure to the ambient.
U.S. Pat. No. 4,150,771 is the most pertinent of the above cited patents and discloses a closure unit having a two-way valve, adapted to be used with a beer keg. However, such closure unit is not operable, by mating with a unitary extracting device, to permit concurrent flow of chemical contents out of the container and flow of atmosphere into the container at one time; and operable at another time, by reason of the mating with that same extracting device, to permit flow of flushing liquid into the container to spray the interior thereof and withdrawal of said flushing liquid. The closure unit of U.S. Pat. No. 4,150,771 is adapted, by the provision of lugs or the like, to engage with several different coupling devices, to achieve the separate operations described therein.
It is therefore a primary object of the present invention to provide a means for restricting access to a container having harmful chemicals as previously noted such that any ability to "open pour" would be essentially inhibited.
A further object is to restrict dispensing of the liquid to the use of specific mating devices to be described so as to leave both units or devices largely free of contamination following completion of the dispensing operation.
Yet another object is to provide full, automatic, re-closure on completion of dispensation so that whether the container were emptied or not, when the extracting or mating device were disconnected, the container would still meet the original objects.
A still further object is to provide an answer to the previously stated problem of handling dangerous chemicals and restricting access to the container, but using comparatively inexpensive means to attain the desired results.